Vinyl chloride polymers plasticized with nonyl phenyl, 2-ethyl hexyl succinates



ijnitedi States Patent 0 VINYL CHLURWE POLYMERS PLASTICIZED WITH NONYLPHENYL, Z-ETHYL HEXYL SUQCTNATES Joachim Dazzi, Dayton, Ohio, assignorto Monsanto (Ihernical Company, St. Louis, Mo., a corporation ofDelaware 6 Claims. (Cl. 260-313) The present invention relates to estersof succinic acid and more specifically provides the new nonylphenyl 2-ethylhexyl succinate and vinyl chloride polymers plasticized with thenew succinate.

An object of the invention is the provision of new derivatives ofsuccinic acid; a further object is the preparation of new and usefulcompounds; still another object of the invention is the provision ofefiicient plasticizers for vinyl chloride polymers. Other objects may behereinafter disclosed.

These objects are accomplished by the following invention wherein thereare prepared new mixed esters of succinic acid substantially accordingto the scheme:

2,709,691 F'atented May 31, 1955 perature and preferably at atemperature of around 0 C.

Since the reaction proceeds by condensation of 1 mole of the phenol with1 mole of the acyl halide, substantially equimolar proportions of thereactants are generally employed; however, an excess of either reactantmay be employed since such an excess may be readily removed from thereaction product. The resulting succinate may be separated from anyother constituents, e. g., diluent, catalyst, or unreacted material bydistillation, extraction, etc.

The present nonylphenyl Z-ethylhexyl succinates are stable, rather highboiling materials which are advantageously employed in the chemical andallied industries for a wide variety of purposes. They are of generalutility as plasticizers for synthetic resins and plastics and especiallyfor vinyl chloride polymers to which polymers they confer a high degreeof flexibility at even very low temperatures.

A wide variety of plasticizers has been employed for the purpose ofimproving the physical properties of vinyl chloride polymers. Particularattention has been given to the improvement of flexibility and heat andlight stability for such plasticized compositions. In many in stancesthe improvement in flexibility has been obtainable only by sacrificingother desirable properties of an ideal polyvinyl chloride composition.We have found that very good flexibility is imparted to vinyl chloridepolymers CHzCO 0 in which R is an alkyl radical of 9 carbon atoms.

Compounds provided by the present invention include Z-rrnonylphenylZ-ethylhexyl succinate, 4-n-nonylphenyl Z-ethylhexyl succinate,Z-isononylphenyl Z-ethylhexyl succinate, 4-isononylphenyl Z-ethy'lhexylsuccinate, Z-tertnonylphenyl Z-ethylhexyl succinate, and 4tert-nonylphenyl succinate. The nonylphenols used for the preparation ofthe present compounds are readily obtainable by alkylation of phenolwith a mono-oleiinic aliphatic hydrocarbon of 9 carbon atoms or with analkyl halide of 9 carbon atoms. Particularly useful are nonylphenolsobtained by alkylation of nonylphenol with the isononene which isobtained by polymerization of propylene. Reaction of the Z-ethylhexylsuccinyl chloride with the nonylphenols to yield the present esters isetiected readily by contacting the phenol with the ester advantageouslyin the presence of an esterifying catalyst at ordinary or increasedtemperatures until formation of the mixed esters has occurred.Esterifying catalysts which may be employed, are basic or acidic agentswhich are substantially inert during the reaction conditions, forexample, inorganic or organic acids or acid reacting salts such assulfuric acid, hydrochloric acid, acetic acid, calcium bisulfite, sodiumor potassium hydroxide, sodium carbonate, pyridine, etc. The reactionmay be effected in the presence or absence of an extraneous diluent. Asdiluents there may be used, c. g., inert liquids such as ether, acetone,dioxane, nitrobenzene, toluene, etc. Advantagcously the reaction iseffected under substantially anhydrous conditions in order to avoidhydrolysis of the acyl halide, and provisions are made for removing thehydrogen halide evolved as it is formed. In order to neutralize theevolved halide it is preferred to conduct the reaction in the presenceof a basic catalyst.

Although temperatures up to the refluxing point of the reaction mixturemay be employed, optimum yields are generally obtained by operating ataround room temwhen the present products are employed as plasticizersfor such polymers.

The nonylphenyl 2-ethylhexyl succinates are valuable plasticizers forpolyvinyl chloride and copolymers of at least 70 per cent by weightofvinyl chloride and up to 30 per cent by weight of an unsaturated monomercopolymerized therewith, for example, vinyl acetate, vinylidenechloride, etc. The present compounds impart great flex: ibility to vinylchloride polymers at very low temperatures; they are compatible withsuch polymers, and show no exudation of plasticizer even at plasticizercontent of up to 50 per cent.

Although the quantity of plasticizer will depend upon the particularpolymer to be plasticized and upon its molecular Weight, it is generallyfound that compositions having from 5 per cent to 50 per cent by weightof plasticizer will, in most cases, be satisfactory for general utility.The good flexibility of the plasticizedcomposition increases withincreasing plasticizer concentration.

In evaluating plasticizer efficiency use is madev of the followingempirical testing procedures:

Compatibility.-Visual inspection of the plasticized composition isemployed, incompatibility of the plasticizer'with the polymer beingdemonstrated by cloudiness and exudation of the plasticizer.

Low temperature flexibiZity.-Low temperature flexibility is one of themost important properties of elastomeric vinyl compositions. While manyplasticizers will produce flexible compositions at room temperature theflexibility of these compositions at a low temperature may varyconsiderably, i. e., plasticized polyvinyl chloride compositions thatare flexible at room temperature often become very brittle and uselessat low temperatures. Low temperature flexibility tests herein employedare according to the Clash-Berg method. This method determines thetorsional flexibility of a plastic at various temperatures. Thetemperature at which the vinyl composition exhibits an arbitrarilyestablished minimum flexibility is defined as the low temperatureflexibility of the composition. This value may also be defined as thelower temperature limit of the plasticized compositions usefulness as anelastomer.

Hardness.A standard instrument made by the Shore Instrument Company isused for this determination and expresses the hardness in units from 1to 100. The hardness of a composition is judged by its resistance to thepenetration of a standard needle applied to the composition under astandard load for a standard length of time.

Volatility-Just as a decrease in low temperature often results indecreased flexibility of a plasticized polymer composition so does adecrease in plasticizer concentration when caused by volatilization ofthe plasticizer. Hence, plasticizers which are readily volatilized fromthe plasticized composition as a result of aging or heating areinefficient because upon volatilization the plasticized compositionsbecome stifi. and hard. The test for plasticizer volatility hereinemployed is that described by the American Society for Testing Materialsunder the designation D-744-44T.

The invention is further illustrated, but not limited, by the followingexamples:

Example 1 Into a 500 m1. three necked flask equipped with a droppingfunnel, mechanical stirrer, and a calcium chloride drying tube there wascharged 44 g. (0.2 mole) of 4-isononylphenol (obtained by reaction ofphenol with a polymeric C9 olefin obtained by polymerization ofpropylene), 150 g. of ether and 30 g. of pyridine. The Whole was thencooled to a temperature of C. and to the cooled mixture there was thenadded, during 1.2 hours, 0.2 mole of 2-ethylhexyl succinyl chloride. Thewhole was then stirred for 40 minutes at a temperature of from 0 C. toC. The reaction product was then washed with water and aqueous sodiumhydroxide and the washed material was distilled to yield 4-nonylphcnylZ-ethylhexyl succinate B. P. 220-240 C./12 mm., 11 1.4813.

Example 2 Sixty parts of polyvinyl chloride and 40 parts by weight ofthe 4-isononylphenyl Z-ethylhexyl succinate of the above example weremixed on a rolling mill to a homogeneous blend. During the milling therewas observed substantially no fuming and discoloration. A molded sheetof the mixture was clear and transparent and substantially colorless.Testing of the molded sheet for low temperature flexibility, accordingto the testing procedure described above, gave a value of minus 34 C.,which value denotes extremely good low temperature properties. Tests onthe volatility characteristics of the plasticized composition gave avalue of 8.5 per cent. When subjected to heat at a temperature of 325 F.for a period of minutes the clarity and color of the molded product weresubstantially unchanged. The plasticized material had a hardness of 81before the volatility test and a hardness of 78 after the volatilitytest.

The very good results obtained by employing 4-isononylphenyl 2ethy1hexylsuccinate as a plasticizer for polyvinyl chloride are suiprising, for4-nonylphenyl esters of succinic acid, generally, cannot be employed asplasticizers for polyvinyl chloride. Thus, 4isononylphenyl(butoxyethoxy)ethyl succinate, which ester has the same number of carbonatoms as do the nonylphenyl Z-ethylhexyl succinates, is incompatiblewith polyvinyl chloride and cannot be used with this polymer to yieldhomogenous compositions containing parts ester and parts polyvinylchloride.

While the above example shows a composition in which the ratio ofplasticizer to polymer content is 40:60, the content of ester topolyvinyl chloride may be widely varied, depending upon the propertiesdesired in the final product. For many purposes a plasticizer contentof, say, from only 10 per cent to 20 per cent is preferred. The presentesters are compatible with polyvinyl chloride over wide ranges ofconcentrations, up to 50 per cent of esters based on the total Weight ofthe plasticized composition yielding desirable products. v

Although the invention has been described particularly with reference tothe use of the present esters as plasticizers for polyvinyl chloride,these esters are advantageously employed also as plasticizers forcopolymers of vinyl chloride, for example, the copolymers of vinylchloride with vinyl acetate, or vinylidene chloride, etc. Preferably,such copolymers have a high vinyl chloride content, i. e., a vinylchloride content of at least per cent by weight of vinyl chloride and upto 30 per cent by weight of the copolymerizable monomer.

The plasticized polyvinyl halide compositions of the present inventionhave good thermal stability; however, for many purposes it may beadvantageous to use known stabilizers in the plasticized compositions.Inasmuch as the present esters are substantially unreactive with thecommercially available heat and light stabilizers which are commonlyemployed with polyvinyl chloride or copolymers thereof, the presence ofsuch materials in the plasticized products does not impair the valuableproperties of the present esters. The present esters are of generalutility in softening vinyl chloride polymers. They may be used as theonly plasticizing component in a compounded vinyl chloride polymer orthey may be used in conjunction with other plasticizers.

This application is a division of my copending application Serial No.228,540, filed May 26, 1951, now Patent Number 2,689,865.

I claim:

1. A resinous composition comprising a vinyl chloride polymerplasticized with an ester having the general formula CzHr CHzCO OCH2CH(CH2)aCHz R in which R is an alkyl radical of 9 carbon atoms.

2. A resinous composition comprising polyvinyl chloride plasticized withan ester having the general formula R in which R is an alkyl radical of9 carbon atoms.

3. A resinous composition comprising polyvinyl chloride plasticized withan ester having the general formula CH2COOOH2CH(CH2)3CH3 .LWOG

in which R is an alkyl radical of 9 carbon atoms.

5. A resinous composition comprising a copolymer of up to 70 per cent byWeight of vinyl chloride and up to 30 per cent by Weight of anunsaturated monomer copoiymerizable therewith, said copolymer beingplasticized with an ester having the general formula 6 in which R is analkyl radical of 9 carbon atoms, said ester being from 5 to 50 per centby Weight of the composition.

6. A resinous composition comprising polyvinyl chloride plasticized with4-nonylphenyl 2-ethy1hexyl succinate.

No references cited.

1. A RESINOUS COMPOSITION COMPRISING A VINYL CHLORIDE POLYMERPLASTICIZED WITH AN ESTER HAVING THE GENERAL FORMULA